Support break and labeled statements.

frog/leg/ssa/optimize.dart

Index: frog/leg/ssa/optimize.dart
diff --git a/frog/leg/ssa/optimize.dart b/frog/leg/ssa/optimize.dart
index 1f1a029aeaf8bff9407fa4bc6569399abff3be31..5d07e406b03f988987bc4ec019f808533f2ffee6 100644
--- a/frog/leg/ssa/optimize.dart
+++ b/frog/leg/ssa/optimize.dart
@@ -295,13 +295,23 @@ class SsaDeadPhiEliminator {
       }
     }
 
+    recursiveRemove(HPhi phi) {
+      while (!phi.usedBy.isEmpty()) {
+        recursiveRemove(phi.usedBy[0]);
+      }
+      phi.block.removePhi(phi);
+    }
+
     // Remove phis that are not live.
     for (final block in graph.blocks) {
       HPhi current = block.phis.first;
       HPhi next = null;
       while (current != null) {
         next = current.next;
-        if (!livePhis.contains(current)) block.removePhi(current);
+        if (!livePhis.contains(current)) {

[ngeoffray, 2012/02/21 13:12:17]

Should we visit post dominator instead?

[Lasse Reichstein Nielsen, 2012/02/21 13:53:56]

That might work if there is no cyclic dependency.
I'll do it this now, and at least not be doing any worse than before.

+          // Remove any (dead phi) uses of current before removing current.
+          recursiveRemove(current);
+        }
         current = next;
       }
     }